Do they fall off easy)?
Not at all. they fit great and comfortable. Keep the good fit when wet.
How can I find width
You do not need width, stretches very well and could walk in the Dead Sea very good !!!
Are these safe for sailing
I used them yesterday at the river and they were pretty good on slippery rocks so pretty much. They have little grip things on the sole. More like water shoes than water socks. You can walk in them too!
Does color fade from swimming pool chlorine?
No they dont fade.
Can i run on treadmill with these?
Sure, I do. I do a lot of walking, treadmill but mostly around the block